1. Field of the Invention
The present invention relates generally to data communication networks having a plurality of wired and/or wireless access servers configured to support remote processing, data storage and voice communication. More specifically, this invention relates to the intelligent routing of packetized voice communication between telephones and radio terminals through wireless and hardwired channels in a data processing network.
While the present invention is described herein with reference to illustrative embodiments for particular applications, it should be understood that the invention is not limited thereto. Those having ordinary skill in the art and access to the teachings provided herein will recognize additional modifications, applications and embodiments within the scope thereof and additional fields in which the present invention would be of significant utility.
2. Description of Related Art
To support data collection, multiple radio base station networks have been developed to overcome a variety of problems with single radio base station networks such as spanning physical radio wave penetration barriers, wasted transmission power by portable computing devices, etc. However, multiple radio base station networks have their own inherent problems.
For example, in a multiple base station network employing a single shared channel, each base station transmission is prone to collision with neighboring base station transmissions in the overlapping coverage areas between the base stations. Therefore, it often proves undesirable for each base station to use a single or common communication channel.
In contradistinction, to facilitate the roaming of portable or mobile devices from one coverage area to another, use of a common communication channel for all of the base stations is convenient. A roaming device may easily move between coverage areas without loss of connectivity to the network.
Such exemplary competing commonality factors have resulted in tradeoff decisions in network design. These factors become even more significant when implementing a frequency hopping spread spectrum network. Frequency hopping is a desirable transmission technique because of its ability to combat frequency selective fading, avoid narrowband interference, and provide multiple communications channels.
Again, however, changing operating parameters between coverage areas creates difficulties for the roaming devices which move therebetween. In particular, when different communication parameters are used, a portable or mobile device roaming into a new base station coverage area is not able to communicate with the new base station without obtaining and synchronizing to the new parameters. This causes a communication backlog in data collection networks.
Such data collection networks and their communication protocols have been specifically designed for data collection and forwarding through wireless and hardwired links. They are designed in attempts to optimize overall data flow through the network. Among other flow optimizing techniques used, the data is segmented and packetized in preparation for transmission. Packet by packet, the data is transmitted as channel bandwidth becomes available.
Thus, instead of disabling a channel by dedicating bandwidth to service only a pair of participants exchanging potentially-large amounts of data (data possibly having no immediate need), the channel is shared by many participants, each sending segments of data in packets whenever an opening in the channel occurs.
In contrast, to support the delivery of real time voice, alternate network design constraints must be considered. For example, such networks often dedicated bandwidth to voice transmission exchanges. However, by dedicating channel bandwidth to voice, efficient communication of data through such networks is seriously impacted. Data communication would have to wait for longer periods of time until dedicated voice bandwidth has been released. Similarly, data communication would have to be immediately discontinued upon requests for voice bandwidth.
Thus, there is a need for a communication network that provides efficient distribution and utilization of network resources in support of both data and voice delivery.
An object of the invention is to provide a method and apparatus wherein seamless voice and data communication is provided among both roaming devices within wireless portions of a communication network and stationary devices within hardwired portions of the network.
Another object of the present invention is to provide a hierarchical communications system for providing an efficient communication pathway for both data and voice.
Other objects, advantages, and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.